<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .container {
            width: 100%;
            background-color: #DDF3F7;
        }

        .wrap {
            padding: 20px;
            overflow: hidden;
        }

        /* 浮动与两侧皆自适应的流体布局写法*/
        .box1 {
            float: left;
            margin-right: 20px;
            background-color: #ccc;
            height: 300px;
        }

        .box2 {
            display: table-cell;
            *display: inline-block;
            width: 1000px;
            background-color: #ccc;
        }

        /*清除浮动造成的影响*/
        .clearfix:after {
            content: '';
            display: table;
            clear: both;
        }

        .clearfix {
            *zoom: 1;
        }
    </style>
</head>

<body>
    <div class="container">
        <div class="wrap clearfix">
            <div class="box1">1212342342</div>
            <div class="box2">12312</div>
        </div>
    </div>
</body>

</html>